Exam 1- Neuraxial Principles (5/28/2024)) Flashcards
(93 cards)
What are the two major components of regional anesthesia?
- Central Neuraxial Blocks
- Peripheral Nerve Blocks
What are the two components of Central Neuraxial Anesthesia?
Which one is harder to perform?
- Spinal Anesthesia
- Epidural Anesthesia (This one is harder to perform, it takes skills.)
Will you expect to see CSF during epidural blocks?
No. CSF should not be expected in epidural blocks.
CSF is expected in spinal blocks.
What structures (in order) will the needle pass through to get to the epidural space? (Midline approach)
- Skin
- Subcutaneous fat
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Dura Mater *will feel a pop
- Subdural space *subtle feeling
- Arachnoid Mater
- Subarachnoid space * confirmation with CSF
What structures in order will the needle pass through during a paramedial spinal block?
- Skin
- Subcutaneous fat
- Ligamentum flavum
- Dura Mater
- Subdural space
- Arachnoid Mater
- Subarachnoid space
Spinal Anesthesia is the injection of local anesthetic (LA) into the ____________ space.
- Subarachnoid
What are two other names for Spinal Anesthesia?
- Subarachnoid Block (SAB)
- Intrathecal Block
Are subarachnoid blocks used primarily as adjunct agents or as the sole anesthetic technique?
SABs can be used both as the primary anesthetic plan and also as adjuncts.
What procedures commonly require a SAB?
- C-section
- Lower extremity surgery
- Abdominal Surgery (Lower/Upper)
Differentiate the onset of action between a spinal block and an epidural block.
Spinal Block: Rapid Onset (5 min)
Epidural Block: Slow Onset (10-15 mins)
Describe the spread of LA between a spinal block and an epidural block.
Spinal Block: Higher than expected; may extend extracranially.
Epidural Block: As expected, can be controlled w/ volume of LA.
Which type of block tends to extend cephalad?
Spinal Block: Higher than expected; may extend extracranially.
Which type of block (spinal or epidural) is much more segmental in nature?
Epidural Block = Segmental
Which type of technique (spinal or epidural) will result in much greater motor neuron blockade?
Spinal Block = Dense motor block
Is hypotension more likely to occur between a spinal block or an epidural block?
- Spinal Block
For SAB, the _______ effect is usually 2 spinal segments cephalad of the sensory block.
- SNS
For SAB, the _______ effect is 2 spinal segments below the sensory block.
- Motor
What are your phrenic nerves?
- C3 nerve fiber
- C4 nerve fiber
- C5 nerve fiber
What LA discussed in class is used for a “walking” epidural.
- Ropivacaine
Ropivacaine provides a very segmental block
What are your cardiac accelerator nerves?
T1 - T4
What term was used in class to describe antagonized sympathetic nerve fibers secondary to local anesthetics?
- Sympathectomy
This usually results in hypotension and bradycardia.
Differentiate the duration of action between a spinal block vs an epidural block.
Spinal: Limited and fixed (one-shot)
Epidural: Unlimited (Catheter in place w/ LA infusion)
Differentiate the level of placement between a spinal block vs an epidural block.
Spinal Block: L3-L4 is bigger, but L4-L5 is what we learn on, L5-S1
Epidural Block: Any Level
Although an epidural can be performed at any level, residents will start at L4-L5.
How many attempts are permitted for a spinal/epidural block?
- Three